Method for handling well casings



A. L. ARMENTROUT METHOD FOR HANDLING WELL cASINGs Jan. 30, 1940.

Original Filed Sept 13 Jan. 30, 1940.

A; L. ARMENTROUT METHOD FOR HANDLING WELL CASINGS Original Filed Sept. 13, 1937 3 Sheets-Sheet 2 6w 7 n I g i T w a; g a

ma J.

1940- A. L. ARMENTROUT I 2,188,589

METHOD FOR HANDLING WELL CASINGS Original Filed Sept. 13, 1937 3 Sheets-Sheet 5 gm WM Patented Jan. 30,

UNITED STATES METHOD FOR HANDLING WELL CASINGS Arthur L. Armentrout,

Los Angeles, Calif., as-

signor or one-third to Elwin B. Hall and onethird to Virgil P. Baker Continuation 01' application Serial No. 163,549, September 13, 1937. This application May 22, 1939, Serial No. 275,119

11 Claims.

This invention relates to the well drilling-art and relates more particularly to methods for installing well casings. A general object of this invention is to provide rapid, simple and effective 5 methods for handling and installing well casings.

This application is a continuation of application Serial No. 163,549, filed September 13, 1937.

When a string of well casing is run into a well it is difiicult, if not impossible, to determine the extent that the casing will project from the mouth of the well when the string is cemented in and put under a suitable tension. Accordingly, when a string of easing has been cemented in a well and put under the desired tension, it is usual to have a substantial portion of the casing project from the well head. This projecting portion must be cut oil to prepare the casing for attachment to the landing head. In setting and landing a string of casing it is very undesirable to release the string as the casing may buckle and distort and the cement seal at its lower end may be fractured by the weight of the casing. For this reason it has heretofore been necessary to provide slips or other holding means in the landing head (hereinafter sometimes referred to as the head) to maintain the casing under tension when its upper part is shortened and packed off in the head- Another object of this invention is to provide a method for landing well casing in which the casing string is maintained under tension from a point below its upper end leaving its upper portion free and unstressed to be out off and secured to the supporting member or head. 5 Another object of this invention isto provide a method for landing well casing that precludes the possibility of the casing settling or buckling 1vilhel it is being prepared for attachment to the Another object of this invention is to provide a method of the character mentioned in which the casing may be welded to the head to be suspended therefrom and to be sealed therewith.

Another object of this invention is to provide a method of the character mentioned in which the portion of casing being welded to the head is free and under no strain so that the weld or wvelds are not under stress during the welding process. In prior attempts to weld casing to landing heads it has been the practice'to engage the projecting upper portion of the casing with an elevator. or the like, to maintain the entire casing string under tension when the weld is to be made. With this procedure the part of the 55 casing being welded to the head is under a heavy tensile strain and is stretched so that severe stresses are set up in the weld or welds. The method of the present invention overcomes this difliculty as the part or the casing welded to the head is relieved oi. all strains at the time of the 6 welding operations.

Another object of this invention is to provide a method of the character mentioned in which simple, inexpensive heads may be employed.

Another object of this invention is to provide 10 a method of the character mentioned that does not require the permanent use of casing slips or spiders at the heads.

Another object of this invention is to provide a method of the character mentioned in which a plurality of strings of casing may be successively landed and suspended from simple, inexpensive heads.

Another object of this invention is to provide a method of the character mentioned that avoids the use of packing means, split rings and other more or less complicated parts liable to fail and allow leakage when the well is completed and under production.

The various objects and features of my invention will be fully understood from the following detailed description of typical preferred forms and applications of the invention, throughout which description reference is made to the accompanying drawings, in which:

Fig. 1 is a longitudinal sectional view of a typical well with a string of casing extending therethrough illustrating the step of putting the casing under tension. Fig. 2 is a view similar to Fig. 1 showing the casing supported under tension on the landing head and illustrating the mandrel and casing gripping tool about to enter the easing. Fig. 3 is a view similar to Fig. 2 showing the tool in gripping engagement with the casing and the mandrel supported by the hoist mechanism of the well to maintain the casing under tension. Fig. 4 is a view similar to Fig. 3 showing the cut off upper portion of the casing being passed over the mandrel while the mandrel is supported by jacks or blocks. Fig. 5 is a view similar to Fig. 4 showing the landing head being passed down over the mandrel. Fig. 6 is a View similar to Fig. 5 showing thelanding head connected with the casing to land or support the same. Fig.7 is an enlarged fragmentary vertical sectional view of a form of head that may be employed in connection with the method, there being a portion of the upper head section broken away to appear in cross section. Fig. 8 is a horizontal detailed sectional view taken as 5 indicated by line 8-8 on Fig. 7. Fig. 91s a view similar to Fig? showing another form of split landing head and Fig. 10 is a horizontal detailed sectional view taken as indicated by line Ill-l0 on Fig. 9.

The present invention is concerned with the setting and landing of well casings of the character employed in deep wells such as oil wells and gas wells. Figs. 1 to 6, inclusive, illustrate a typical well W having an outer casing O cemented in the well W and secured at its upper end to a landing headL. The present invention is not concerned with the setting or landing of the outer casing O and it may be assumed that this casing has been previously set and landed. An inner casing C extends longitudinally through the outer casing 0 from the lower end of the well to the top of the well. I will first proceed with a detailed description of a preferred manner of carrying out the method of the invention utilizing a head H that is to be threaded to the casing C, to land or suspend the same, and will later describe the manner of carrying out the method when employing the welded on type head.

The method of the present invention, as illustrated in Figs 1 to 6, inclusive, may be said to comprise, generally, cementing the lower endof the casing C in the well W, putting the casing C under tension, maintaining the casing C under tension by supporting it on the landing head L through the medium of a supporting element or spider i l, introducing a mandrel l2 and a tool l3 into the casing C to grip the casing below the head L whereby the casing may be put under tension by a hoist mechanism M, cutting off the upper portion P of the casing C, alternately supporting the mandrel l2 by the hoist mechanism M and the head L to provide for the removal of the cutoff portion P, passing the head H over the mandrel IE to the head L while alternately supporting the mandrel I2 on the head L and the hoist mechanism M to maintain the casing C under tension and then securing the casing C to the head H.

The casing C is assembled and run into the well W in the usual manner and is then cemented. The lower end portion of the casing C is cemented in the open lower part of the well to provide a shut ofi or seal about the casing and to secure the lower part of the casing in the well. The cementing operation may be performed in any selected manner and this operation is well known to those skilled in the art. Figs. 1, 2, 4 and 5 show the casing C cemented in the well W.

When the cement at the lower end of the casing C has set and hardened the elevator l I may be engaged under a collar l8 on the upper end of the casing C and the hoist mechanism M maybe operated to take the desired stretch in the casing. When this has been done the split spider I4 is arranged about the upper part of the casing and is supported on' the head L or any other suitable support. The slips 22 of the spider I 4 maybe arranged in place so that the spider serves to support the casing C on the head L for the maintenance of the tension on the casing. With-thei; spider in active holding engagement with the casing C the elevator II is disengaged fromlthe casing, and the collar 18 is unthreaded from the upper end of the casing. While the required tension is being maintained on the casing C by the elevator H or by the spider M the casing is marked as illustrated at X-at the point where it is to be cut preparatory to its connection with the head H.

Following the above operations the mandrel I! provided with the tool I 3 is connected with the hoist mechanism M through the medium of the elevator II or a similar device. The elevator II is engaged about the mandrel I2 to cooperate with an upper collar 20 so that it suspends the mandrel from its upper end. The mechanism M is then operated to lower the mandrel l2 into the casing C. The mandrel I2 is lowered to bring the tool l3 to a point below the plane of the upper end of the head L. With the tool l3 in this position the mandrel I2 is operated or manipulated to actuate the tool l3 so that it grips the interior of the casing C. The hoist mechanism M is then operated to place an upward strain on the casing C through the medium of the mandrel l2 and the tool l3. The hoist mechanism M is set or locked to maintain the desired tension on the casing C. The split spider is then removed from about the casing C to expose the portion of the casing above the head L so that the casing may be severed or out along the line X. Any suitable cutting toolmay be employed to cut the casing.

The cutting of the casing C at the line X of course frees the projecting upper portion P and this free portion P is passed upwardly from the mandrel I2. The portion P is first moved upwardly to a position on the mandrel between the spaced collars 20 and M and the split spider It is assembled or arranged about the mandrel below the collar 2|. The slips 22 are arranged in the spider M to cooperate with the lower end of the collar 2! and the spider is jacked up or blockedup to maintain the tension on the mandrel l2 and the casing C. Figs. 4 and 5,0f the drawings illustrate the spider l6 blocked up by blocks 25 resting on the head L. Hydraulic jacks or screw jacks may be employed to jack up the spider it. With the spider H5 in holding cooperation with the collar 2!, as shown in Figs. 4 and 5, the elevator H may be disconnected from the mandrel l2 so that the cut off portion P may be passed upwardly from the upper end of the mandrel and removed. Subsequent to the removal of the cut off casing portion P and while the spider M is engaged under the lower collar 2| the head H is lowered down over the upper portion of the mandrel l2 to the spider M, as shown in Fig. 5. The elevator ll is then engaged under the upper collar 20 and the hoist mechanism M is operated so that the elevator ll bears upwardly against the collar 20 to maintain the necessary tension on the casing C. The spider It may be removed from about the mandrel 12 to allow the head H casing C is threaded by means of a split die or a special thread milling tool, or, if desired, may be threaded by a typical die passed downwardly over the mandrel I! while alternately engaging the collars 20 and 2| with supporting means'to maintain the tension on the casing.

This threading operation is, of course, performed before the head H is brought to its final position on the head L. Following the connection per portion of the casing C to rest on the head L. k The head sections 30 are then connected together arcane tion and the hoist mechanism is operated to release the tool i3 and to withdraw the tool I3 and the mandrel I2 from the casing C.

The invention contemplates the variation of the above described method by welding the casing C to the head H instead of threading the head to the casing. After the head H has been arranged on the landing head L and secured to the landing head L the casing may be welded to the head H. At this time the casing C is maintained under the selected tension by the tool l3 engaging in the casing, as described above. In this connection it is important to note that the tool I3 engages in the casing C below the head H so that the portion of the casing C being welded to the head H is free of all tension and strain. Ac-

cordingly, the weld or welds are not made at a stretched or stressed part of the casing and the finished weld or welds are secure, dependable and devoid of stresses. The weld or welds connecting the casing C with the head H preferably form a closure or seal about the casing to prevent the escape of fluid and pressure, although if desired the head H may be provided with packing means for this purpose. It will be readily understood how the weldin operation may be substituted for the threading of the head H to the casing C in the method described in detail above.

An important and time saving variation in the above described method is provided by the invention. The-method of the invention provides for the use of a. sectional supporting member or head for suspending or supporting the casing C., A sectional supporting member or head may be readily assembled about the protruding portion of the casing C to rest on the head L while the tension is maintained on the casing C by the tool l3, the mandrel l2, etc. and the casing may be then secured to the supporting member or head. The invention contemplates the employment of sectional supporting members or head fittings varying greatly in character and construction. In Figs. '7 to 10, inclusive, I have illustrated two forms oi sectional heads H and H of the drawings are divided or split so that they may be readily arranged about the protruding upper portion of the casing C. The head H illustrated in Figs. 7 and 8 is divided on a vertical diametric plane to constitute two complementary sections 38. In carrying out the method of the invention while employing the head H the casing C is put under tension and its upper portion P is cut off at X and removed, all as described above. Following the removal of the cut oil portion P and while the casing C is maintained under tension by the tool [3, the mandrel i2 and the elevator II, as illustrated in Fig. 6, the head sections are assembled about the protruding upto form an annular or tubular assembly and the head assembly is secured to the head L. In the 1 case illustrated in Figs. '7 and 8 the sections 38 are connected by-welding 3| to constitute a continuous annular structure and the head H is secured to the head L by welding 32.

head H.

p of the following claims.

Following the assembling and connecting oi the head sections 38 the upper end part of the casing C is welded to the head H. A continuous annular weld 40 may be made to connect the casing C to the head H and to provide a dependable seal about the casing. As illustrated in Figs. 3 6,

inclusive, of the drawings, the tooll3 engages in the casing C below the upper end part of the easing so that at the time of making'the weld 48 the, part of the casing C receiving the weld is in a normal unstressed condition and is not distortedv or stretched. and the weld jOinsor unites the metal oi'the tree casing with the metal of the head H. The weld .40 is not strained or-weakened by reason of elongation, contraction or other distortion of the casing C and, therefore, con stitutes a strong, dependable connection between the casing and the head H. At the completion oi the weld 48 the mandrel i2 is manipulated to release the tool l3 and thetool i3 and the mandrel l2 are withdrawn from the casing and the This completes the operation.

The head H illustrated in Figs. 9 and 10 of the drawings is an annular or tubular supporting member divided along a vertical diametric plane to constitute two sections 34. The head sections 34 are adapted to be assembled about the protruding upper portion of the casing C following theremoval ofthe cut off portion P and while the casing is maintained under tension by the tool i3, the mandrel l2 andthe hoisting mechanism M. .The head sections 34 are adapted to rest on the landing head L and are adapted to be connected to constitute an annular structure or assembly. Bolts passed through flanged portions 36 of the sections 34 may connect the two sections and welding 31 may secure the head H to the head L. When the sections 34 have been secured together and attached to the head L the casing C is secured to the head H It is preferred to weld the casing C to the head H A continuous annular weld 38 may secure the upper end of the casing C to the upper end part of the head H The weld 38 is made while the casing C is maintained under tension by the engagement oi the tool' i3 in the casing. As the tool i3 is engaged in the casing C some distance below the upper end of the casing the portion of fluid and pressure from around the casing. Fol-' lowing the completion of the weld 38 the mandrel I2 is manipulated to free the tool l3 andthe tool and the mandrel are withdrawn from the casing- 0 to complete the operation.

It is to be observed that the head H and the head K may have extensive contact with the casing C below the welds 40 and 38 to dampen or prevent vibration of the casing. This extensive contact of the head with the casing prevents vibration of the casing from effecting the weld at the upper end of the casing.-

Having described only typical preferred forms and applications of my inventiomI do not wish to be limited or restricted to the specific details herein set forth,'but wish to reserve to myself any variations or modifications that may appear 1. A method of landing a well casing comprising placing the casing under tension by en-" gaging the interior of the casing with a tentension is maintained on the casing, passing the cut oil portion of casing upwardly from the tensioning means while tension is maintained on said means, passing a head down over the tensioning means to a support, welding the casing to the head while the tension is maintained thereon, and then removing the tensioning means from the casing so that the weld suspends the tensioned casing from the head.

2. A method of landing a well casing on a landing head comprising inserting a tool into the upper end of the casing for gripping the interior of the casing at a point below the landing head and so that it projects upwardly beyond the casing, applying a pull on the tool to maintain the casing under tension, cutting off the portion of the casing above the point where it is gripped by the tool, passing the cut off portion of the casing upwardly from the tool, passing a head down over the tool, welding the upper end of the casing to the last named head while the tension is maintained on the casing, and then removing said tool from the casing so that the welding suspends the tensioned casing from said last named head.

3. A method of landing a well casing comprising placing the casing under tension by engaging the interior of the casing with a tensioning means, cutting ofi' an upper portion of the casing at the point where the landing head is to be arranged and above where the casing is engaged by the tensioning means while the tension is maintained on the casing, passing a landing head down over the tensioning means to a support, and then securing the casing to the head.

4. A method of landing a well casing comprising placing'the casing under tension by engaging the casing with a tensioning means, cutting off an upper portion of the casing at a point above where the casing is engaged by the tensioning means and while the tension is maintained on the casing, arranging a support about the tensioned casing to reston the well head, welding the casing to the support to seal the casing and support together and to connect thecasing and support together with the casing under tension, and then disengaging the tensioning means from the casing to leave the easing suspended onthe well head through the medium of the welding and support.

5. The method of suspending a well casing from the landing head of a well comprising temporarily maintaining the casing under tension by engaging the casing with a tensioning tool at a point removed from the head, arranging a support around the casing to rest on the head, welding the casing and support together while the casing is maintained under tension by said tensioning means, and then disassociating the said tensioning tool from the casing to leave the casing suspended under tension from the head by said support.

6. The method of suspending a well casing from the landing head of a well comprising p1acing the casing under tension by engaging the casing with a tensioning means unassociated with the head and operating the tensioning means, assembling a sectional support about the casing and on the head, welding the casing to the support while the casing is held under tension by the w tensioning means, and then disengaging the tensioning means from the casingwhereby the tension is maintainedon the casing by-the support I welded to the casing and bearing on the head.

'7. The method of handling a well casing comting the casing under tension by a hoist means,

assembling a sectional support about the upper portion of the casing while the casing is maintained under'tension, welding the casing to the support while the casing is under tension, and then disengaging the hoist means from the casing so that the said tension is maintained on the casing by the said support.

8. The method of handling a well casing comprising running the easing into the well, sealing the lower portion of the casing in the well, putting the casing under tension by engaging the casing at a point below its upper end with a tensioning means, arranging a sectional support aboutthe upper portion of the casing above said point while the casing is under tension, welding the casing to the support above said point while the casing is maintained under tension by the tensioning means, and then disengaging the tensioning means from the casing sothat the support maintains the tension on the casing.

9. The method of handling a well casing comprising running the easing into the well, cementing the lower portion of the casing in the well, putting the casing under tension by engaging the casing at a point below its upper end with a tensioning means operated by a lifting means and then operating the lifting means, cutting off an upper portion of the casing, assembling a sectional support about the casing, welding the casing to the support, the said cutting, assembling 'and welding operations being performed while the casing is maintained under tension by said means, and then releasing the tensioning means from the casing so that the tension is maintained on the casing by the suport.

10. The method of handling a well casing comprising running the casing into the well, cementing the lower portion of the casing in the well, putting the casing under tension by engaging the casing at a point below its upper end with a tensioning means operated by a liftingmeans and then operating the lifting means, cutting ofi an upper portion of the casing, assembling a sectional support about the casing, connecting together the sections of said support, welding the upper end of the casing tosaid support, said cutting, assembling, connecting and welding operations being performed while the casing is maintained under tension by said means, and then releasing the tensioning means from the casing to allow the support to assume and mainto leave the casing suspended under tension from the support.

ARTHUR L. ARMEN'I'ROUT. 

